JPH0122334Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to gas insulated electrical equipment such as gas insulated switchgear, gas shields, and disconnectors.

This type of gas-insulated electrical equipment is constructed by housing electrical equipment such as disconnectors and disconnectors in metal containers filled with insulating gas, and insulating spacers are provided at the connections between the containers. gas separation between containers is achieved. In this case, the insulating spacer is disposed such that its flange portion is sandwiched between the flange portions of adjacent metal containers, and is fastened with a bolt passing through the flange portion of the metal container and the insulating spacer. An annular groove for filling with rust preventive agent is provided at the joint between each flange and the insulating spacer.
The annular groove is filled with a rust preventive agent to prevent the flange from rusting. For example, FIG. 1 shows a connection part of a metal container used in a conventional gas insulated switchgear. Insulating spacer sandwiched between 2a, 4
is an O-ring for keeping the joint between the flange portions 1a, 2a and the insulating spacer 3 airtight. The flange portions 1a, 2a and the insulating spacer 3 are connected by a connecting means consisting of a bolt 5 passing through them and nuts 6, 6 screwed to both ends of the bolt 5, and the containers 1 and 2 are gas-divided by the spacer 3. connected to each other. In this example, in order to prevent rust on the flange parts 1a and 2a, an annular groove 7 extending in the circumferential direction is provided on the surface of the flange parts 1a and 2a facing the spacer 3. 8 is filled. However, in conventional devices of this type, no measures were taken to prevent rust preventive from leaking at the joints between the insulating spacer and each flange. There were cases where the liquid leaked from the outer periphery of the container to the outside of the container or penetrated to the O-ring. If the rust preventive agent leaks outside, there will be a lot of material loss and it will take a long time to inject the rust preventive agent, which is undesirable. This is not desirable as it requires a lot of time. Furthermore, metal containers are made of mild steel, stainless steel, aluminum, etc., while insulating spacers are made of epoxy cast products, etc., and insulating spacers generally have a larger coefficient of thermal expansion than metal containers. Therefore, when the ambient temperature changes, a force is exerted that causes a misalignment between the flange of the metal container and the flange of the insulating spacer. This creates a large stress within the outer periphery of the insulating spacer, which can cause cracks in the spacer. Something happened. Since this crack develops due to repeated heating and cooling cycles, it will eventually become impossible to maintain airtightness within the metal container, which may lead to a major accident.

An object of the present invention is to provide a gas-insulated electrical device that prevents leakage of rust preventive agent and prevents cracks from occurring in insulating spacers.

The present invention includes an annular gasket that extends concentrically with the annular groove in areas adjacent to the inner and outer peripheries of the annular groove for filling the rust preventive agent at the joint between the flange of the metal container and the insulating spacer. By appropriately selecting the material of each gasket, the coefficient of friction between each gasket and the insulating spacer is made smaller than the coefficient of friction between the flange portion and the insulating spacer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The gas insulated electrical equipment of the present invention will be explained in detail below with reference to the illustrated embodiments.

Figure 2 shows the main parts of an embodiment in which the present invention is applied to gas-insulated electrical equipment such as gas-insulated switchgear. In the figure, 11 and 12 are tubular metal containers, and 13 is epoxy resin This is an insulating spacer made of an insulating material such as. Metal containers 11 and 12
have flange portions 11a and 12a, respectively,
An insulating spacer 13 is inserted between these two flanges. As shown in FIG. 3, an annular groove 14 extending in the circumferential direction is formed on the surface of the flange portions 11a and 12a of the metal containers 11 and 12 facing the insulating spacer. A groove 15 for arranging an O-ring is formed at the position. The flange portions 11a and 12a also have an annular groove 1.
Bolt insertion holes 16, 16, . Through holes 17, 17, . . . that align with the bolt insertion holes 16, 16, .
a, 12a each bolt insertion hole 16 and spacer 1
Nuts 19 are screwed onto both ends of the bolt 18 inserted into the through hole 17 of No. 3 and tightened. An O-ring 20 is disposed within the O-ring groove 15, and this O-ring constitutes an air-tight retaining portion that maintains the air-tightness within the containers 11 and 12. A bulging portion 22 that supports a conductor connection portion 21 is formed in a portion of the insulating spacer 13 located inside the metal container, and the conductor connection portion 21 is provided with a bulge portion 22 for supporting a conductor connection portion 21. The live parts are electrically and mechanically connected, and devices in adjacent metal containers 11 and 12 are electrically connected to each other via the conductor connection part 21. When equipment for three phases is housed in the metal containers 11 and 12, three bulges 22 are provided in a triangular arrangement, and a conductor connection portion 21 is provided in each bulge.

In the present invention, the flange portions 11a, 1
Annular groove 1 at the joint between 2a and the insulating spacer 13
Annular gaskets 23 and 24 are interposed in areas adjacent to the inner and outer peripheries of 4, respectively. In this embodiment, the wall thickness of the portions of each flange portion adjacent to the inner and outer circumferential portions of the annular groove 14 is formed slightly thinner, so that when each flange portion is butted against an insulating spacer, the inner circumference of the annular groove 14 is slightly thinner. A slight gap is formed in each of the areas adjacent to the periphery and the outer periphery. Into these gaps are inserted annular gaskets 23 and 24 made of a material having lubricity (in this case, the property of having a sufficiently small coefficient of friction with other substances). The annular gaskets 23 and 24 of this embodiment are made of polytetrafluoroethylene (PTFE) in the form of strings or strips. As shown in flange portions 11a to 11b
be pasted on. In this case, gaskets 23, 24
Applying an adhesive to the surface in contact with the flange of the gasket makes it easier to attach the gasket. The gasket (made of PTFE) used in this example is string-like and has marshmallow-like elasticity before being tightened, and when it is sandwiched between the flange and the insulating spacer and tightened, it becomes a film. and is interposed between each flange portion and the spacer. Since this gasket has lubricating properties, the coefficient of friction between the gasket and the insulating spacer is smaller than the coefficient of friction between the insulating spacer and the flange when they are in contact with each other. Therefore, due to the difference in thermal expansion coefficient between the flange portions 11a and 12a of the container and the insulating spacer, when a force is applied to cause a misalignment between the two, a misalignment easily occurs between the two, so the insulating spacer It is possible to prevent large stress from being generated near the outer periphery of the insulating spacer, and it is possible to prevent cracks from occurring in the insulating spacer.

The rust preventive agent 25 to be filled into the annular groove is one that initially has fluidity and then hardens over time. Room temperature vulcanizable silicone rubber (RTV) is suitable as such a rust preventive agent.

When connecting the metal containers 11 and 12 of the above embodiment, first, before joining the flange portions 11 and 12 to the insulating spacer 13, the flange portions 11a and 12a are
Attach gaskets 23 and 24 to predetermined locations. Next, an O-ring 20 is placed in the groove 15, an insulating spacer 13 is inserted between the flanges 11a and 12a, and the bolts 18 are sequentially inserted into each bolt insertion hole 16 and through hole 17, and nuts are inserted into both ends of the bolts 18. 19,
19 and tighten. Then, a bolt is not inserted into at least one bolt insertion hole 16 of each flange portion, and the annular groove 14 is inserted through the bolt insertion hole.
A rust preventive agent 25 is injected into the inside. In this case, since the gaskets 23 and 24 are provided at the portions adjacent to the inner and outer peripheries of the annular groove 14 at the joints between the flange portions 11a and 12a and the insulating spacer 13, the gaskets 23 and 24 are injected into the annular groove 14. The rust preventive agent fills the annular groove without leaking to the outside. Further, the rust preventive agent does not enter the O-ring part. After the injection of the rust preventive agent is completed, insert the bolt into the last bolt insertion hole and tighten the nut.
The connection of the second flange portions 11a and 12a is completed. The rust inhibitor hardens at room temperature after being injected.

In the above explanation, it is assumed that the wall thickness of the part of each flange portion where the gasket is placed is made slightly thinner to form a gap between each flange portion and the insulating spacer for inserting the gasket. Instead of forming an annular groove, a gasket may be inserted between the insulating spacer and the regions adjacent to the inner and outer circumferences of the annular groove of each flange.

In the above embodiment, the annular groove for filling the rust preventive agent is provided on the flange side of the metal container, but this annular groove may be provided on at least one of the flange portion and the insulating spacer. An annular groove may be provided in both the insulating spacer and the insulating spacer.

In the above embodiment, the bolt is inserted into the through hole provided in the insulating spacer 13, but it is also possible to embed a filler metal in the outer periphery of the insulating spacer 13 and insert the bolt into the through hole provided in the filler metal. Alternatively, a bolt may be screwed into a screw hole provided in the filler metal.

As described above, according to the present invention, an annular gasket is interposed between the inner and outer circumferential portions of the annular groove for filling the rust preventive agent at the joint between the flange portion of the metal container and the insulating spacer. Therefore, the rust preventive agent can be prevented from leaking to the outside, and the rust preventive agent can also be prevented from entering the inner peripheral side. Therefore, the time required for injecting the rust preventive agent can be shortened, and the rust preventive agent can be prevented from being wasted or attached to unnecessary parts. In addition, the material of the gasket is selected so that the coefficient of friction between the gasket and the insulating spacer is smaller than the coefficient of friction between the flange and the insulating spacer. Since the insulating spacer is allowed to be displaced when a force that tends to cause relative displacement is applied, it is possible to prevent cracks from occurring in the insulating spacer.
Equipment reliability can be increased.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a main part showing a connection part of a metal container of a conventional gas-insulated electrical equipment, Fig. 2 is a cross-sectional view showing a main part of an embodiment of the present invention, and Fig. 3 is used in the same embodiment. FIG. 4 is a partially sectional front view showing a half portion of the flange portion of the metal container, and FIG. 4 is a sectional view showing a state in which a gasket is attached to the flange portion of the metal container. 11, 12...metal container, 11a, 12a...
Flange portion, 13... Insulating spacer, 14... Annular groove, 18... Bolt, 19... Nut, 23,
24...Gasket, 25...Rust preventive agent.

Claims (1)

[Scope of utility model registration request] A plurality of metal containers each having a flange portion and housing equipment inside are arranged, and the flange portions of adjacent metal containers are joined via an insulating spacer, and the surfaces of the flange portions and the insulating spacer to be joined to each other are In a gas-insulated electric device in which a circumferentially extending annular groove provided on at least one side is filled with a rust preventive agent, the inner and outer circumferential portions of the annular groove at the joints between the respective flange portions and the insulating spacer. An annular gasket extending concentrically with the annular groove is interposed in a region adjacent to each of the annular grooves, and a coefficient of friction between each gasket and the insulating spacer is smaller than a coefficient of friction between the flange portion and the insulating spacer. A gas insulated electrical device characterized in that the material of the gasket is selected so as to.